Sayyiduna Abu Hurayrah (may Allah be pleased with him) narrates that a man stood up and asked the Messenger of Allah (peace and blessings be upon him): "May a man pray in a single garment?" The Messenger of Allah (peace and blessings be upon him) said: "Does every one of you have two garments?" Then another man came and stood before Sayyiduna Umar (may Allah be pleased with him) and asked him about praying in a single garment, and Sayyiduna Umar (may Allah be pleased with him) said: "When Allah has given you abundance, then you too should be generous with yourselves. You should gather your garments: tie on a waist-wrapper and with it wear an upper sheet, a shirt or a cloak; or wear trousers and with them an upper sheet, a shirt or a cloak; or wear short drawers and with them a cloak or a shirt." Sayyiduna Abu Hurayrah (may Allah be pleased with him) says: I think he also mentioned an upper sheet with the short drawers.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 3275